Apparatus for heating surfaces



Feb. 2-8, 1933.` G. H. LUTZ 1,899,704

l APPARATUS FOR HEATING SURFACES Filed Jan. 28, 1952 3 Sheets-Sheet 1` s. H. L .U'rz

APPARATUS FOR HEATING SURFACES 3 Sheets-Sheet 2 Filed Jan. 28', 1952 v'rT/yrrf u @n 'f Feb. 28,-1-933. G, H, ILU`TZ 1,899,704

APPARATUS FOR HATING SURFACES Filed Jan. 28, 1952 5 Sheets-Sheet 3 1 h Il ji 11f El 0 ply a large volume of air to the furnace, anda- Patented Feb. 2,8, 1933 encuen HINmoN LU'rz,

or CHICAGO, ILLINOIS' APPARATUS ron HEATING sUnFAcEs Application filed January 28., 1932, Serial No. 589,488, and in France November r23, 1931. 'y 1 Y This invention relates to an apparatus for heating surfaces, especially surfaces that are approximately horizontal, such as pavements, which apparatus can be mounted upon any mobile or stationaryfoundation carrying the said equipment for its operation. This ap#` paratus consists of a furnace or heatingchamber, at one end of which is located a means foru burning liquid fuel, a fan serving to supheat spreading and heat conning member, such as a hoo whereby the hot gaseous medium is brought into contact with the surface to be heated.

The large volume of .air passing through the heating chamber is mixed with the products of combustion passing into said heat confining member or covering member adapted to direct the gaseous heating agent `against o the surface to be heated.

caping gases also cause damage to the curbs of adjacent sidewalks, which usually are made of material, such as limestone, which contains moisture, and this being expanded b the heat causes fractures of the curbing.

oreover, damage is done by the hot gases to the rubber tires of nearby vehicles, and specially to the tires of the truck by which the apparatus itself is carried.

The main object of this invention is to prevent this waste and injury; and for the accomplishing of that object it provides means whereby the hot gases whichescape under the edges of the hood or heat spreading member are returned again to the heating chamber. This salvaged hot air is of such high temperature when returned to the furnace that it requires but a very small .amount of fuel'to bring it back again to the operating temperature.

When it is desired to heat an object or surface beyond the edgel of the hood, ,then one or more of the adjustable parts of the return conduit may be so moved as to allow the hotfair to escape to the atmosphereJ t0 l Y heatV such object or surface.

If the cycle y*of operation were prolonged Y indefinitely without ythe admission' of. fresh air the oxygen supporting combustion would be quickly exhausted. Owing'to the irregular surfaces usually heated ay small amount of theV hotl air will ordinarily escape to the atmosphere allowing ythe sameamount of fresh air to be admitted to thereturn conduit. In addition such fresh air as.' desiredV v fan. To'prevent the hood from coming into intimate contact with ya surface that might beso ktrue as to prevent escape of the hot gases froin'thev inner hood, there are attached to the hood shoes or runners which prevent such intimatecontact. Y i i The invention will be fully understood upon referenceto the accompanying draw-` ings in which: Fig. lis an elevation of the apparatus in which .are shown ythe essentialparts;

Fig. 2 is a top C-C of Fig. 1 l v Fig. 3 s a sectional View of Fig. l cutv at Fig. .Lis a section of Fig. 2 cut at B-B; Fig. 5 is an end view of Fig. 1; .F ig. 6 showsv a different construction` of yapparatus for accomplishing the saine -result g,

Fig. 7 is'a top view of a'section on line A1A1`of Fig. 6.

The apparatus illustrated in the drawings.

,comprises afurnace or heaterl of any suitable type, lhaving av refractory lining 2; kan I oil burner 3; and an air-chamber 4., The necessary air for combustion and heat ling the surface is suppliedlby fany 5 and'delivered by conduit 6 to chamber 4. The products of combustion and hot air-,are forced through furnace l and conduit 7 intohood 8 `onto arpavement or otherpsurface 9.

For the purpose of returning the hot air ,that would otherwise be discharged into the atmosphere, a secondary hoodflOis fitted to `.hood 8,. A Bymeansof the suctionpfthe fan 5l the hot air is drawn from hood l0 through conduit l11. 12 is a variable opening to the view4 ofa section online 75 'lio zico

atmosphere to permit of the addition of fresh air.

This outer conduit or hood may be provided at 13 with movable shutters to allow the hot air to blow beyond theconfines of the hood when desired. Shoes or runners 14 are provided to prevent a too close Contact of the hood with the surface to be heated.

In the embodiment of the invention illustrated in Figs. 6 and 7 the. two hoods 8 and 10 are concentric andthere is a space between them which serves as a passageway forthe return of the gases to the furnace. Flue l1 is likewise concentrically disposed with re,- spect to flue 7 Itis obvious that any changes in the details of construction will not alter the principles ofthe operation of this invention.l

Having thus described my invention what I claim as new thereimand' desire to secure by-Letters patent is :l

l. An apparatus for heating surfaces com prising-in combination, a chamber, means for forcingl air into said chamber at one end thereof, fuel burningmeans located insaid chamber, a heaty spreading and confining member for covering' the surface to be heated, a conduit for connecting said hood with the other end of said chamber, and means located adjacent said hood for catching the used hot gases which pass the edges of said heat spreading member and returning them back again` to said chamber.

Lgaseous medium over and against the surface to be heated and a second hood so disposed as to catch the gaseous medium escaping around the edge of said first, named hood and to conduct it back to said supplying means.

In testimonyl ywhereof I have signed this '-1 specification.v f

- GEORGE HINTON LUTZ.

2. An apparatus for heating surfacescom- Y prisinginpcombination, a chamber, a fan for vforcing air into said chamber at one end thereof, a fuel burner located-in said chamber,'a hood for covering the surface to be heated, a conduit for connecting said hood with the other end of said chamber, a second hood located adjacent the first mentioned one, and a conduitfor connecting said second hood with the inlet of said fan for returning lcnhe used hot gases-back again to said cham'- 3. An apparatus according t'o claim' 1 further comprising means for admitting fresh a'ir Vinto said secondary conduit.

' Y 4. An apparatus according to claim 2 further comprising means forY admitting fresh 'y air into they second mentioned conduit.

5. lAn apparatus according to' claim 2 ink which the second mentioned hoodsurrounds the iirst mentionedv one.

'6; An apparatus according to claim 2 in which the second mentioned hood surrounds Y 'the first mentioned one, and the second menl ti'oned conduit is concentrically disposed around the first mentioned one.-

7. An apparatusV forl heatingsurfaces,

comprising-means for supplying aheated gaseous medium, a heat spreading and con- Y iining lmember adapted to discharge 'l said l gaseous medium against the surface to be heated, and means for catching the'gaseous .medium escaping-around the edgeof said 

